Perhaps you should try some spelling variations:
"modified rough approximation algorithm" » "modified rough approximation algorithms", "modified rough approximations algorithm", "modified one approximation algorithm"
"modified parameters estimation algorithms" » "modified parameter estimation algorithms", "modified parameter estimates algorithms", "modified parameter optimization algorithms", "modified parameters estimation algorithm", "modified parameters optimization algorithms", "modified parameters optimisation algorithm"

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• Performing a fuzzy search may retrieve terms with similar spellings: (("modified parameters estimation algorithms") OR ("modified rough approximation algorithm"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"modified parameters estimation algorithms\") OR (\"modified rough approximation algorithm\"))*".
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